#使用sys模块来退出游戏，pygame模块开发游戏功能
import sys				
import pygame
from pygame.sprite import Group
from settings import Settings
from game_stats import GameStats
from scoreboard import Scoreboard
from ship import Ship
from alien import Alien
from button import Button
import game_functions as gf

def run_game():
	# 初始化游戏，设置和屏幕对象
	pygame.init()
	ai_settings = Settings()
	screen = pygame.display.set_mode(
		(ai_settings.screen_width,ai_settings.screen_height))
	pygame.display.set_caption("Alien Invasion")
	
	# 创建一个用于存储游戏统计信息的实例,并创建积分牌
	stats = GameStats(ai_settings)
	sb = Scoreboard(ai_settings, screen, stats)
	
	# 创建一个Play按钮
	play_button = Button(ai_settings, screen, "Play")
	# 创建一个飞船，一个子弹编组，一个外星人编组
	ship = Ship(ai_settings, screen)
	bullets = Group()
	aliens = Group()
	# 创建外星人群
	gf.creat_fleet(ai_settings, screen, ship, aliens)
	
	clock = pygame.time.Clock()
	time_passed = 0
	# 开始游戏的主循环
	while True:
		ai_settings.time_passed = clock.tick(40) / 10
		gf.check_events(ai_settings, screen, stats, play_button, 
			ship, aliens, bullets)
		
		if stats.game_active:
			ship.update()
			gf.update_bullets(ai_settings, screen, stats, sb, 
				ship, aliens, bullets)
			gf.update_aliens(ai_settings, stats, screen, 
				ship, aliens, bullets)
			
		gf.update_screen(ai_settings, screen, stats, sb, ship, aliens, 
			bullets, play_button)
		
run_game()
